This invention relates to a process for the preparation of polytriazines. More specifically, it relates to novel catalysts for the preparation of polytriazines from aromatic polycyanates.
It is known from Sundermann et al., U.S. Pat. No. 4,094,852, June 13, 1978, that aromatic cyanates can be polymerized to prepare polytriazine polymers. Such polymers are prepared by contacting the aromatic cyanates with suitable catalysts at elevated temperatures. It is taught that suitable catalysts include acids, bases, salts, nitrogen and phosphorus compounds, for example, Lewis acids such as AlCl.sub.3, BF.sub.3, FeCl.sub.3, TiCl.sub.4, ZnCl.sub.2, SnCl.sub.4 ; proton acids such as HCl, H.sub.3 PO.sub.4 ; aromatic hydroxy compounds such as phenol, p-nitrophenol, pyrocatechol, dihydroxy naphthalene, sodium hydroxide, sodium methylate, sodium phenolate, trimethylamine, triethylamine, tributylamine, diazobicyclo-(2,2,2)-octane, quinoline, isoquinoline, tetrahydroisoquinoline, tetraethyl ammonium chloride, pyridine-N-oxide, tributylphosphine, phospholine-.DELTA..sup.3 -1-oxa-1-phenyl, zinc octoate, tin octoate, zinc naphthenate and mixtures thereof.
Oehmke, U.S. Pat. No. 3,694,410, Sept. 26, 1972, teaches that chelates of metal ions of the nonionic type or the ionic type, with 1 to 6 or more chelate rings, can catalyze the preparation of polytriazines from aromatic polycyanates.
It is desirable to use a catalyst in the preparation of polytriazines from aromatic polycyanates in which the polymerization time is short.